1. Technical Field
The present invention relates a switch assembly structure in which a first switch element and a second switch element are adapted to be selectively operated by a single operating knob.
2. Related Art
FIG. 3 shows a schematic plan view of a power seat switch in a vehicle. This power seat switch is composed of a first switch device 1 on the right side and a second switch device 2 on the left side. A cover 4 corresponding to the first switch device 1 and a cover 5 corresponding to the second switch device 2 are mounted on a common switch body 3.
The first switch device 1 is so constructed as to operate a reclining switch for adjusting a reclined angle of a back of a seat and a head restraint switch for adjusting a height of a head restraint provided on a top of the seat back. In the cover 4 of the first switch device 1 is formed a guide hole 4a in a shape of a cross and a cut-out 4b so as to be adjacent to each other as shown in FIG. 4. A projection 3a provided on a switch body 3 is inserted into the cut-out 4b and projects upward from the cover 4.
A plate 6 is fixed to the switch body 3 underneath the cover 4. The plate 6 is provided with a guide hole 6a in a shape of a cross, and an elongated guide hole 6b so as to be adjacent to each other. A knob holder 7 is slidably mounted on the plate 6. The knob holder 7 has a projection 7a which is adapted to be inserted into the guide hole 4a on its upper face, and two projections 7b and 7c which are adapted to be inserted into the guide holes 6a and 6b respectively on its lower face. Two holders 8, 9 are disposed underneath the plate 6 at positions below the guide holes 6a and 6b, respectively. Into recesses 8a and 9a formed in the holders 8 and 9 respectively, the corresponding projections 7b and 7c are adapted to be inserted. The recess 8a of the holder 8 into which one of the projections 7b is inserted extends in a direction of an arrow A1, while the recess 9a of the holder 9 into which the other projection 7c is inserted extends in a direction of an arrow A2 which intersects the direction A1.
A coil spring 10, a bifurcated member 11, and a pair of contact blades 12 are disposed below each of the holders 8, 9. The switch body 3 is provided with fixed contacts (not shown) corresponding to the contact blades 12 respectively. A pair of the contact blades 12 corresponding to the holder 9 and the mating fixed contacts constitutes the reclining switch 13 as a switch element, while a pair of the contact blades 12 corresponding to the holder 8 and the mating fixed contacts will constitute the head restraint switch 14 as a switch element.
A single operating knob 15 is fitted to the above described projection 3a and the projection 7a of the knob holder 7. A guide part 16 consisting of a pair of ribs 16a, and an engaging tubular part 17 are provided on a back face of the operating knob 15. The projection 3a is inserted into the guide part 16, and the projection 7a is inserted into the engaging tubular part 17.
In the above described structure, when the knob holder 7 is operated to move in the direction of the arrow A1 in FIG. 3 by operating the operating knob 15, the holder 9 moves in the same direction, and the reclining switch 13 is actuated with this movement. On this occasion, since the holder 8 will not be moved, the head restraint switch 14 will not be actuated.
When the knob holder 7 is operated to move in the direction of the arrow A2 in FIG. 3 by operating the operating knob 15, the holder 8 moves in the same direction, and the head restraint switch 14 is actuated with this movement. On this occasion, since the holder 9 will not be moved, the reclining switch 13 will not be actuated.
On the other hand, the second switch device 2 on the left side has a front vertical switch 18 for adjusting a front part of the seat in a vertical direction, a slide switch 19 for adjusting back and forth positions of the seat, and a rear vertical switch 20 for adjusting a rear part of the seat in a vertical direction. These three switches 1819, and 20 are adapted to be operated by a single operating knob 21. These three switches 18, 19 and 20 are of a same fundamental structure. As shown in FIG. 5, each of the switches 18, 19 and 20 is composed of a movable member 22 provided with a projection 22a, and a coil spring 10, a bifurcated member 11, a pair of contact blades 12 and fixed contacts (not shown) on the switch body 3 which are similar to those elements provided in the switches 13, 14.
The aforesaid cover 5 is provided with three guide holes 5a, 5b and 5c into which the projections 22a of the movable members 22 are inserted respectively. In these three guide holes 5a to 5c, the center guide hole 5b extends in a direction of an arrow B1 in FIG. 3. The projection 22a of the corresponding movable member 22 is inserted into the guide hole 5b. The left and right guide holes 5a and 5c extend in a direction of an arrow B2 in FIG. 3, and the projections 22a of the corresponding movable members 22 are respectively inserted into the guide holes 5a and 5c.
In the above described structure, when the operating knob 21 of the second switch device 2 is operated in the direction of the arrow B1, the movable member 22 in the center part moves in the same direction, and the slide switch 19 is actuated with this movement. On this occasion, the left and the right movable members 22 do not move, and both the front and the rear vertical switches 18, 20 are not actuated.
When a left part of the operating knob 21 in FIG. 3 is operated in the direction of the arrow B2, the left side movable member 22 moves in the same direction, and the front vertical switch 18 is actuated. On this occasion, the center and the right hand movable members 22 in FIG. 3 do not move, and both the slide switch 19 and the rear vertical switch 20 is not actuated.
When a right part of the operating knob 21 in FIG. 3 is operated in the direction of the arrow B2, the right side movable member 22 moves in the same direction, and the rear vertical switch 20 is actuated. On this occasion, the center and the left hand movable members 22 in FIG. 3 do not move, and both the slide switch 19 and the front vertical switch 18 are not actuated.
When the entire operating knob 21 is operated in the direction of the arrow B2 in FIG. 3, both the left hand and the right hand movable members 22 synchronously move in the same direction, and both the front and the rear vertical switches 18, 20 are actuated. On this occasion, the center movable member 22 does not move, and the slide switch 19 is not actuated.
In this case, the above described first switch device is so constructed that the single operating knob 15 can selectively actuate either of the reclining switch 13 and the head restraint switch 14. On this occasion, these two switches 13 and 14 are prevented from being simultaneously actuated by the two projections 7b, 7c provided on the lower face of the knob holder 7 and the two guide holes 6a, 6c of the plate 6.
However, a cost for the switch assembly of this structure is high, because it requires a number of components such as the knob holder 7, the plate 6 and the two holders 8, 9 in addition to the operating knob 15 and the cover 4, and a number of assembling steps accordingly. Moreover, the knob holder 7, the plate 6 and the holders 8, 9 cannot be used commonly as the components for the second switch device 2, and must be manufactured for exclusive use. It is a further drawback that a large space is required in a direction of a depth.